AdGuard Scriptlets and Redirect Resources

AdGuard's Scriptlets and Redirect resources library which provides extended capabilities for content blocking.

• Scriptlets
  • Syntax
    • Blocking rules
    • Exception rules
  • Available scriptlets
  • Scriptlets compatibility table
  • Trusted scriptlets
    • Restriction
    • Available trusted scriptlets
• Redirect resources
  • Syntax
  • Available redirect resources
  • Redirect resources compatibility table
• Development
  • How to build
  • How to test
  • How to link packages
  • How to update wiki
• Usage
  • CoreLibs
  • NPM module
• API description
  • Scriptlets API
    • invoke()
    • getScriptletFunction()
    • Properties
      • SCRIPTLETS_VERSION
  • Redirects API
    • Redirects class
    • getRedirect()
    • isBlocking()
    • getRedirectFilename()
  • Validators API
    • isValidScriptletName()
    • isValidScriptletRule()
    • isAdgScriptletRule(), isUboScriptletRule(), isAbpSnippetRule()
    • isValidAdgRedirectRule()
    • isRedirectResourceCompatibleWithAdg()
  • Converters API
    • convertUboToAdg()
    • convertAbpToAdg()
    • convertScriptletToAdg()
    • convertAdgToUbo()
    • convertAdgRedirectToUbo()
• Browser compatibility
• Projects using Scriptlets

Scriptlets

Scriptlet is a JavaScript function which can be used in a declarative manner in AdGuard filtering rules.

AdGuard supports a lot of different scriptlets. Please note, that in order to achieve cross-blocker compatibility, we also support syntax of uBO and ABP.

Syntax

Blocking rules

[domains]#%#//scriptlet(name[, arguments])

• domains — optional, a list of domains where the rule should be applied;
• name — required, a name of the scriptlet from AdGuard Scriptlets library;
• arguments — optional, a list of string arguments (no other types of arguments are supported).

Remarks

• The meaning of the arguments depends on the scriptlet.

• Special characters in scriptlet argument must be escaped properly:

  • valid:
    • 'prop["nested"]'
    • "prop['nested']"
    • 'prop[\'nested\']'
    • "prop[\"nested\"]"
  • not valid:
    • 'prop['nested']'
    • "prop["nested"]"

• Scriptlet name and each of the arguments should be wrapped in quotes. You can use either single or double quotes for the scriptlet name and arguments. Single quote is recommended but not for cases when its usage makes readability worse, e.g. ".css('display','block');" is more preferred then '.css(\'display\',\'block\');'.

Exception rules

[domains]#@%#//scriptlet([name[, arguments]])

• domains — optional, a list of domains where the rule should be applied;
• name — optional, a name of the scriptlet to except from the applying; if not set, all scriptlets will not be applied;
• arguments — optional, a list of string arguments to match the same blocking rule and disable it.

Examples

1. Apply the abort-on-property-read scriptlet on all pages of example.org and its subdomains, and passes one argument to it (alert):

   example.org#%#//scriptlet('abort-on-property-read', 'alert')

2. Remove the branding class from all div[class^="inner"] elements on all pages of example.org and its subdomains:

   example.org#%#//scriptlet('remove-class', 'branding', 'div[class^="inner"]')

3. Apply set-constant and set-cookie on any webpage, but because of specific scriptlet exception rule only set-constant scriptlet will be applied on example.org and its subdomains:

   #%#//scriptlet('set-constant', 'adList', 'emptyArr')
   #%#//scriptlet('set-cookie', 'accepted', 'true')
   example.org#@%#//scriptlet('set-cookie')

4. Apply adjust-setInterval on any webpage, and set-local-storage-item on all pages of example.com and its subdomains, but there is also multiple scriptlet exception rule, so no scriptlet rules will be applied on example.com and its subdomains:

   #%#//scriptlet('adjust-setInterval', 'count', '*', '0.001')
   example.com#%#//scriptlet('set-local-storage-item', 'ALLOW_COOKIES', 'false')
   example.com#@%#//scriptlet()

• Scriptlets list
• Scriptlets compatibility table

Trusted scriptlets

Trusted scriptlets are scriptlets with extended functionality. Their names are prefixed with trusted-, e.g trusted-click-element, to be easily distinguished from common scriptlets.

Restriction

Trusted scriptlets application must be restricted due to dangerous nature of their capabilities. Allowed sources of trusted scriptlets are:

• filters created by AdGuard Team,
• custom filters which were installed as trusted,
• user rules.

Trusted scriptlets has no compatibility table as they are not compatible with any other blocker.

Trusted scriptlets list

Redirect resources

AdGuard is able to redirect web requests to a local "resource".

Syntax

AdGuard uses the same filtering rule syntax as uBlock Origin. Also, it is compatible with ABP $rewrite=abp-resource modifier.

$redirect is a modifier for the basic filtering rules so rules with this modifier support all other basic modifiers like $domain, $third-party, $script, etc.

The value of the $redirect modifier must be the name of the resource that will be used for redirection. See the list of available redirect resources.

Priority of $redirect rules is described in the Knowledge Base.

Examples

• ||example.org/script.js$script,redirect=noopjs — redirects all requests to script.js to the resource named noopjs.
• ||example.org/test.mp4$media,redirect=noopmp4-1s — requests to example.org/test.mp4 will be redirected to the resource named noopmp4-1s.

uBlock Origin specifies additional resource name none that can disable other redirect rules. AdGuard does not support it, use $badfilter to disable specific rules.

• Redirect resources list
• Redirect resources compatibility table

Development

How to build

Install dependencies:

pnpm install

Build dist:

pnpm build

In tsurlfilter directory install and link dependencies, link scriptlets, move into package and build, and create tsurlfilter link.

lerna bootstrap

pnpm link --global "@adguard/scriptlets"

cd ./packages/tsurlfilter
pnpm build
yarn link

In extension directory install dependencies, link packages and build

yarn

yarn link @adguard/scriptlets
yarn link @adguard/tsurlfilter

yarn dev

How to test

Some tests are run in QUnit, some in Jest.

Run all tests:

pnpm test

1. QUnit is used for testing of scriptlets, redirects, and helpers:

   pnpm test:qunit [scriptlets | redirects | helpers]

   For scriptlets and redirects test run can be more specific:

   // node test run
   pnpm test:qunit scriptlets --name set-cookie
   pnpm test:qunit redirects --name ati-smarttag
   
   // gui test run
   pnpm test:qunit scriptlets --name set-cookie --gui
   pnpm test:qunit redirects --name ati-smarttag --gui

   For debugging purposes after some test is running in gui mode, you may change your scriptlet/redirect code, and without stopping the server run in new terminal:

   pnpm test:qunit scriptlets --name set-cookie --build

2. Run all jest tests:

   pnpm test:jest

   or limit the testing — testRegex may be specified in jest.config.js or specify test name in command line, e.g.:

   pnpm test:jest -t isValidScriptletRule

To run browserstack tests create .env file or copy and rename .env-example.

Fill in <username> and <key> with data from your Browserstack profile. Run next command:

pnpm browserstack

Tests run by jest should be named .spec.js, so they will be not included in the QUnit tests.

Debugging

Use debugger; statement where you need it, run

pnpm test

and open needed HTML file from tests/dist in your browser with devtools

How to link packages

Scriptlets library relies on external packages, such as @adguard/agtree. During development, you might need to link these packages using pnpm link.

How to update wiki

There are two scripts to update wiki:

1. pnpm wiki:build-table — checks compatibility data updates and updates the compatibility table. Should be run manually while the release preparation.
2. pnpm wiki:build-docs — updates wiki pages about-scriptlets.md and about-redirects.md. They are being generated from JSDoc-type comments of corresponding scriptlets and redirects source files due to @scriptlet/@redirect and @description tags. Runs automatically while the release build.

Usage

CoreLibs

For CoreLibs usage you should use dist/scriptlets.corelibs.json and dist/redirects.json.

File example:

{
    "version": "1.0.0",
    "scriptlets": [
        {
            "names": [
                "abort-on-property-read",
                "ubo-abort-on-property-read.js",
                "abp-abort-on-property-read"
            ],
            "scriptlet": "function() { ...code... }"
        }
    ]
}

Schema:

{
    "type": "object",
    "properties": {
        "version": {
            "type": "string"
        },
        "scriptlets": {
            "type": "array",
            "items": {
                "type": "object",
                "properties": {
                    "names": {
                        "type": "array",
                        "items": {
                            "type": "string"
                        }
                    },
                    "scriptlet": {
                        "type": "string"
                    }
                }
            }
        }
    }
}

NPM module

Installation

You can install the library using

• Yarn: yarn add @adguard/scriptlets
• NPM: npm install @adguard/scriptlets
• PNPM: pnpm add @adguard/scriptlets

API description

Scriptlets API

You are welcome to use scriptlets as a CJS modules or ESM modules:

const { scriptlets } = require('@adguard/scriptlets');
// or
import { scriptlets } from '@adguard/scriptlets';

invoke()

/**
 * Returns scriptlet code by `source`.
 *
 * @param source Scriptlet properties.
 *
 * @returns Scriptlet code.
 * @throws An error on unknown scriptlet name.
 */
declare function getScriptletCode(source: Source): string;
declare const scriptlets: {
    invoke: typeof getScriptletCode;
};

where Source is:

interface Source {
    /**
     * Scriptlet name
     */
    name: string;
    /**
     * Arguments for scriptlet function
     */
    args: string[];
    /**
     * {'extension'|'corelibs'} engine Defines the final form of scriptlet string presentation
     */
    engine: string;
    /**
     * Version
     */
    version: string;
    /**
     * flag to enable printing to console debug information
     */
    verbose: boolean;
    /**
     * Source rule text is used for debugging purposes.
     *
     * @deprecated since it is not used in the code anymore.
     */
    ruleText?: string;
    /**
     * Domain name, used to improve logging
     */
    domainName?: string;
    /**
     * Optional unique identifier for a scriptlet instance.
     *
     * This identifier is used to prevent multiple executions of the same scriptlet on the page.
     * If provided, this `uniqueId` will be combined with the scriptlet's `name` and `args`
     * to create a unique identifier for the scriptlet call. This identifier is
     * stored in the `Window.prototype.toString` object to ensure the scriptlet
     * is not executed more than once in the same context.
     *
     * By avoiding multiple executions, it helps in reducing redundant operations and
     * potential side effects that might occur if the same scriptlet is called multiple times.
     *
     * If `uniqueId` is not specified, no such unique identifier is created, and the
     * scriptlet can be called multiple times.
     */
    uniqueId?: string;
}

getScriptletFunction()

/**
 * Returns scriptlet function by `name`.
 *
 * @param {string} name Scriptlet name
 *
 * @returns {Function} — Scriptlet function.
 */
declare function getScriptletFunction(name: any): string;
declare const scriptlets: {
    getScriptletFunction: typeof getScriptletFunction;
};

Properties

SCRIPTLETS_VERSION

type: string

Current version of scriptlets library.

Redirects API

You are welcome to use redirects as a CJS modules or ESM modules:

const { Redirects } = require('@adguard/scriptlets/redirects');
// or
import { Redirects, getRedirectFilename } from '@adguard/scriptlets/redirects';

Redirects class

import { Redirects } from '@adguard/scriptlets';

/**
 * Converts rawYaml into JS object with sources titles used as keys
 */
const redirects = new Redirects(rawYaml)

where rawYaml is a string with YAML content located in dist/redirects.yml.

getRedirect()

/**
 * Returns redirect source object by title
 */
const redirect = redirects.getRedirect('noopjs');

/**
 * Redirect is an object with following props:
 * {
 *     title: 1x1-transparent.gif
 *     comment: http://probablyprogramming.com/2009/03/15/the-tiniest-gif-ever
 *     contentType: image/gif;base64
 *     content: R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
 * }
 */

isBlocking()

/**
 * Check if redirect is blocking, e.g. click2load.html
 */
const isBlocking = redirect.isBlocking('click2load.html');

getRedirectFilename()

import { getRedirectFilename } from '@adguard/scriptlets/redirects';
/**
 * For a given name or alias of redirect returns the corresponding filename
 * @param name Name or alias of redirect
 * @returns Redirect's filename with extension
 */
declare function getRedirectFilename(name: string): string;

Validators API

isValidScriptletName()

import { isValidScriptletName } from '@adguard/scriptlets/validators';

/**
 * Checks whether the `name` is valid scriptlet name.
 * Uses cache for better performance.
 *
 * @param name Scriptlet name.
 * @returns True if scriptlet name is a valid one or an empty string,
 * otherwise false.
 */
declare function isValidScriptletName(name: string | null): boolean;

isValidScriptletRule()

/**
 * 1. For ADG scriptlet checks whether the scriptlet syntax and name are valid.
 * 2. For UBO and ABP scriptlet first checks their compatibility with ADG
 * by converting them into ADG syntax, and after that checks the name.
 *
 * ADG or UBO rules are "single-scriptlet", but ABP rule may contain more than one snippet
 * so if at least one of them is not valid — whole `ruleText` rule is not valid too.
 *
 * @param rule Any scriptlet rule — ADG or UBO or ABP.
 *
 * @returns True if scriptlet name is valid in rule.
 */
declare function isValidScriptletRule(rule: string | ScriptletInjectionRule): boolean;

isAdgScriptletRule(), isUboScriptletRule(), isAbpSnippetRule()

/**
 * Checks if the `rule` is AdGuard scriptlet rule
 *
 * @param rule - rule text
 * @returns true if given rule is adg rule
 */
declare function isAdgScriptletRule(rule: string): boolean;

/**
 * Checks if the `rule` is uBO scriptlet rule
 *
 * @param rule rule text
 * @returns true if given rule is ubo rule
 */
declare function isUboScriptletRule(rule: string): boolean;

/**
 * Checks if the `rule` is AdBlock Plus snippet
 *
 * @param rule rule text
 * @returns true if given rule is abp rule
 */
declare function isAbpSnippetRule(rule: string): boolean;

isValidAdgRedirectRule()

/**
 * Checks if the `rule` is **valid** AdGuard redirect resource rule
 *
 * @param rule - rule text
 * @returns true if given rule is valid adg redirect
 */
declare function isValidAdgRedirectRule(rule: string): boolean

isRedirectResourceCompatibleWithAdg()

/**
 * Checks if the specified redirect resource is compatible with AdGuard
 *
 * @param redirectName - Redirect resource name to check
 * @returns - true if the redirect resource is compatible with AdGuard
 */
declare function isRedirectResourceCompatibleWithAdg(redirectName: string): boolean;

Converters API

import {
    convertUboToAdg,
    convertAbpToAdg,
    convertScriptletToAdg,
    convertAdgToUbo
} from '@adguard/scriptlets/converters';

convertUboToAdg()

/**
 * Converts string of UBO scriptlet rule to AdGuard scriptlet rule
 *
 * @param rule UBO scriptlet rule
 * @returns array with one AdGuard scriptlet rule
 *
 * @deprecated
 */
declare function convertUboToAdg(rule: string | ScriptletInjectionRule): string[];

Note that parameters in UBO rule should be separated by comma + space. Otherwise, the rule is not valid.

convertAbpToAdg()

/**
 * Convert string of ABP snippet rule to AdGuard scriptlet rule
 *
 * @param rule ABP snippet rule
 * @returns array of AdGuard scriptlet rules, one or few items depends on Abp-rule
 */
declare function convertAbpToAdg(rule: string | ScriptletInjectionRule): string[];

convertScriptletToAdg()

/**
 * Converts any scriptlet rule into AdGuard syntax rule.
 * Comments and non-scriptlet rules are returned without changes.
 *
 * @param rule Rule.
 *
 * @returns Array of AdGuard scriptlet rules: one array item for ADG and UBO or few items for ABP.
 * For the ADG `rule` validates its syntax, and returns an empty array if it is invalid.
 */
declare function convertScriptletToAdg(rule: string | ScriptletInjectionRule): string[];

convertAdgToUbo()

/**
 * Converts AdGuard scriptlet rule to UBO syntax.
 *
 * @param rule AdGuard scriptlet rule
 * @returns UBO scriptlet rule
 * or undefined if `rule` is not valid AdGuard scriptlet rule.
 */
declare function convertAdgToUbo(rule: string | ScriptletInjectionRule): string | undefined;

convertAdgRedirectToUbo()

/**
 * Converts Adg redirect rule to Ubo one
 * 1. Checks if there is Ubo analog for Adg rule
 * 2. Parses the rule and checks if there are any source type modifiers which are required by Ubo
 *    and if there are no one we add it manually to the end.
 *    Source types are chosen according to redirect name
 *    e.g. ||ad.com^$redirect=<name>,important  ->>  ||ad.com^$redirect=<name>,important,script
 * 3. Replaces Adg redirect name by Ubo analog
 *
 * Note: if adg redirect uses UBO's priority syntax, it will be lost on conversion, e.g:
 * ||example.com$redirect=noopjs:99 => ||example.com$redirect=noop.js
 *
 * @param rule adg rule
 * @returns converted ubo rule
 * @throws on incompatible rule
 */
declare function convertAdgRedirectToUbo(rule: string): string;

Browser Compatibility

| Browser | Version | |-----------------------|:--------| | Chrome | ✅ 55 | | Firefox | ✅ 52 | | Edge | ✅ 15 | | Opera | ✅ 42 | | Safari | ✅ 13 | | Internet Explorer | ❌ |

Projects using Scriptlets

• CoreLibs (updates automatically)
• TSUrlFilter
• FiltersCompiler (tsurlfilter's update might be required as well)
• AdguardBrowserExtension (tsurlfilter also should be updated)
• AdguardForSafari (adguard-resources should be updated)
• AdguardForiOS (tsurlfilter should be updated in advanced-adblocker-web-extension)